Patent GB-828540-A (GB)
Title: Improvements in or relating to data processing equipment
Inventor: WRIGHT ESMOND PHILIP GOODWIN
IPC: H04L12/54
Filed: 1956-08-30
Abstract: 828,540. Circuits employing bi-stable magnetic elements; automatic exchange systems. STANDARD TELEPHONES & CABLES Ltd. Aug. 16, 1957 [Aug. 30, 1956], No. 26517/56. Classes 40 (4) and 40 (9). [Also in Group XIX] In equipment in which items of intelligence are stored permanently or semi-permanently in respective rows of a ferro-magnetic storage matrix, from which any one of the stored items may be transferred to a temporary storage device in order to be available for use in connection with a data processing operation, whereafter it is returned to its row of the matrix, the item stored in a row may be changed by transferring it to the temporary storage device, cancelling it from that device, inserting the new item of intelligence into the device, and transferring the new item to that row of the matrix from which the old item was extracted. As described, the equipment is a translator for a telephone exchange and the items of intelligence are translations. The storage matrix is indicated at TA, TB (Fig. 1), a first group of key sets KX, KY controlling an access selector XY, consisting of a co-ordinate array of ferromagnetic cells each of which is individual to one row of the storage matrix, serving to select the row of contents of which are to be changed. Typical circuits associated with key KX1, key KY1 and the core XY11 of the access selector are shown in Fig. 2. All cells of XY are threaded by a bias winding 1 which biases them to negative saturation and each cell also has a row winding 2, a column winding 3, an input winding 5, and an output winding 4 connected to the gates GW, Gr (Fig. 1), associated with the corresponding row of the storage matrix. One of the keys of each of the sets KX, KY having been operated to indicate the row whose translation is to be changed, one key in each of the sets KA, KB (Fig. 1), constituting a second group of key sets, is operated to indicate the new translation, and the start key ST is operated. Pulses from the generator PG (Fig. 2) then drive the distributer PD, the pulses t1, t2 . . . t6 occurring at its outputs sequentially during one cycle. Closure of STB causes the GX gate and the GY gate corresponding to the two operated keys of KX and KY to be primed so that when PD steps to position 1 the corresponding X and Y trigger circuits (for example, XI and YI) are operated to the " 1 " condition and thus register the identity of the wanted row. When PD steps to position 2, the gates (such as G1, G2), controlled by these trigger circuits, open and pulses are passed to the column and row wires of the wanted cell in the access selector XY. This renders that cell unsaturated, in which state it is effective as a pulse transformer to pass the pulse t2 applied to its input winding 5 to the output winding 4 of the same cell, whence it is applied to the xy input of the reading gate Gr1 (Fig. 4), of the wanted row of the storage matrix. Pulse t2 is also directly applied to all Gr gates and hence a read pulse is extended to the wanted row. A decimal digit is stored in the appropriate portion TA or TB of a row by setting one cell thereof to " 1 " and the other nine to " 0," so that when the wanted row is read, " 1 " is read from one of the column wires of TA and " 1 " is read from one of those of TB. Each column wire is connected to an amplifier, such as A3 (Fig. 3), whose output is applied via a t2-controlled gate to a trigger circuit such as RA1 or RB1, so that one trigger circuit RA and one RB will be set to its " 1 " state to register the translation which was stored in the wanted row. With PD in position 3, all the trigger circuits RA and RB are restored to the " 0 " state and the translation registered by them is thus cancelled. When PD steps to position 4 one gate GKA and one gate GKB, primed by the two closed keys of KA, KB, open and pulse t4 set the corresponding trigger circuits RA and RB to the " 1 " state to register the new translation. PD then steps to position 5, whereupon t5 re-operates the across selector XY to prime the Gr and GW gates of the wanted row, of which the GW gate opens to pass the half-write pulse t5a, derived from generator WG (Fig. 2), to the row concerned. At the same time, half-write pulses are applied to the column wires associated with the trigger circuits RA and RB which have been set to " 1," via t5-controlled gates, such as G6 (Fig. 3), and write amplifiers. The cells of the wanted row which are appropriate to the new translation are thus set to store " 1 ". PD steps on to position 6 and stops there, the t6 pulse resetting all the trigger circuits RA, RB, X and Y to the " 0 " state, and priming gate G8 (Fig. 2). On restoration of the start key ST a pulse is applied via G8 to reset PD to its rest position O. Specifications 719,288, 749,796, 750,636 and 828,539 are referred to.